Surgical fastener applying apparatus

ABSTRACT

A surgical fastener applying apparatus including a cartridge supporting section and an anvil supporting section. The cartridge supporting section includes a distal section and a proximal section and the anvil supporting section and cartridge supporting section are configured to clamp tissue therebetween. The anvil supporting section has a distal fastener receiving region, a proximal clamping region and an intermediate region between the fastener receiving region and the clamping region. The proximal clamping region is positioned on a first side of the cartridge supporting section and the fastener receiving region is positioned on a second opposing side of the cartridge supporting section.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.14/372,469, filed Sep. 19, 2014, which is a National Stage Applicationof PCT/US2013/020838 under 35 U.S.C. § 371 (a), filed Jan. 9, 2013,which claims the benefit of and priority to U.S. Provisional PatentApplication Ser. No. 61/587,879 filed Jan. 18, 2012. The entire contentsof each of the above applications are hereby incorporated by reference.

BACKGROUND Technical Field

The present disclosure relates to a surgical fastener applying apparatusand, more particularly, to a surgical fastener applying apparatus havingboth reusable and disposable components.

Background of Related Art

Surgical fastener applying apparatus grasp or clamp tissue betweenopposing jaw structures and join the tissue by means of surgicalfasteners. In some such apparatus, a knife is provided to cut the tissuewhich has been joined by the fasteners. The fasteners are typically inthe form of surgical staples, although other surgical fasteners may alsobe utilized, such as, for example, clips or two part polymeric surgicalfasteners.

Surgical fastener applying apparatus typically include two elongatedbeam members which are used to capture or clamp tissue therebetween.Typically, one of the beam members carries a disposable cartridgeassembly which houses a plurality of staples arranged in at least twolateral rows, while the other beam member includes an anvil whichdefines a surface for forming the staple legs as the staples are drivenfrom the cartridge assembly. Where two part fasteners are used, the beammember which includes the anvil carries a mating part of the two partfastener, e.g. the receiver. Generally, the staple formation process isaffected by the interaction between one or more longitudinally movingcamming members and a series of individual staple pushers. As thecamming members travel longitudinally through the cartridge carryingbeam member, the individual staple pushers are biased upwardly into abackspan of the staples supported within the cartridge assembly tosequentially eject the staples from the cartridge. A knife may beprovided to travel with the camming members between the staple rows tocut the tissue between the rows of formed staples. An example of such aninstrument is disclosed in U.S. Pat. No. 7,631,794, which isincorporated herein in its entirety by reference.

Although reusable fastener applying apparatus have been developed, suchapparatus can be overly complex and prove difficult to sterilize.Because of the difficulties associated with properly sterilizing afastener applying apparatus for reuse, fastener applying apparatus aretypically configured as disposable apparatus. In such disposableapparatus, the cartridge assembly may be replaced to perform multiplefastener applying operations on a single patient, although the fastenerapplying apparatus is typically disposed after the surgical procedurehas been completed. This need for disposability may increase the costsassociated with surgical procedures.

Therefore, a need exists in the art for a fastener applying apparatuswhich includes reusable components, is not overly complex, and isconfigured to facilitate proper sterilization after use in a surgicalprocedure.

SUMMARY

In accordance with one aspect of the present disclosure, a surgicalfastener applying apparatus is provided comprising a cartridgesupporting section and an anvil supporting section, the cartridgesupporting section including a distal section and a proximal section andthe anvil supporting section and cartridge supporting section configuredto clamp tissue therebetween. The anvil supporting section has a distalfastener receiving region, a proximal clamping region and anintermediate region between the fastener receiving region and theclamping region. The proximal clamping region is positioned on a firstside of the cartridge supporting section and the fastener receivingregion being positioned on a second opposing side of the cartridgesupporting section.

In some embodiments, the cartridge receiving section includes a pinextending transversely therefrom and the intermediate region includes anotch for receiving the pin.

In some embodiments, the intermediate region extends alongside thecartridge supporting section. Preferably, the distal section of thecartridge supporting section is configured to receive a disposableloading unit containing a plurality of fasteners and the proximalsection is configured to receive a firing unit for firing the pluralityof fasteners.

In some embodiments, the firing unit includes a firing knob and aplurality of cam bars movable to fire the fasteners wherein the firingknob and cam bars are disposable.

In some embodiments, the disposable loading unit is loadable into thecartridge supporting section in a first direction and the firing unit isloadable into the cartridge supporting section in a second differentdirection.

The cartridge supporting section can include a first elongated channelopening to a first side of the cartridge supporting section forsupporting a disposable loading unit containing a plurality offasteners. The cartridge supporting section can include a second channelopening to a second opposite side of the cartridge supporting sectionfor supporting a firing unit.

The anvil supporting section can include an anvil having a plurality ofpockets facing the cartridge supporting section.

The surgical fastener applying apparatus can further include a lockingmechanism positioned on the proximal end of the anvil supporting andcartridge supporting sections engageable when the sections are moved tothe clamped position.

In another aspect, the present disclosure provides a surgical fastenerapplying apparatus comprising a cartridge supporting section and ananvil supporting section having a distal anvil portion and a proximalhandle portion. The cartridge supporting section and anvil supportingsection are configured to clamp tissue therebetween when in anapproximated position, wherein movement of the proximal handle portionin a first direction toward the cartridge supporting section moves thedistal anvil portion in a second opposite direction toward the cartridgesupporting section.

In some embodiments, the proximal handle portion forms a clamping leverfor pivoting the anvil supporting section relative to the cartridgesupporting section wherein the clamping lever is movable from anunclamped position to a clamped position to releasably secure the anvilsupporting section in close approximation with the cartridge supportingsection.

The apparatus may further include a firing unit including a firing knoband a pair of cam bars operatively connected to the firing knob, thefiring knob movable from a first proximal position to a second distalposition to fire fasteners supported in the cartridge supportingsection. In some embodiments, the firing knob and the cam bars aredisposable.

The anvil supporting section can include an anvil having a plurality ofpockets, the pockets facing a first side of the cartridge supportingsection and the proximal handle portion facing a second opposite side ofthe cartridge supporting section.

The apparatus may further include a locking mechanism positioned on theproximal end of the anvil supporting and cartridge supporting sectionsengageable when the sections are moved to the clamped position.

In accordance with another aspect of the present disclosure a toploading surgical fastener applying apparatus is provided comprising acartridge supporting section including an elongated channel forsupporting a disposable loading unit containing a plurality offasteners. The disposable loading unit is top loaded into the cartridgereceiving section on a first top side. An anvil supporting sectionincludes a distal anvil portion and a proximal handle portion movablefrom an unclamped position to a clamped position to releasably securethe anvil supporting section in close approximation with the cartridgesupporting section. The proximal handle portion includes a lockingmember to engage the cartridge supporting section. A firing assemblyincludes a firing knob movable from a first proximal position to asecond distal position to fire fasteners supported in the disposableloading unit.

In some embodiments, the firing assembly is bottom loaded into thecartridge supporting section.

The apparatus can further include a conical hinge extending transverselyfrom the cartridge supporting section engageable with the anvilsupporting section.

Preferably, the firing assembly is disposable and the cartridgesupporting and anvil supporting section are sterilizable and reusable.

In some embodiments, the distal anvil portion and a proximal handleportion are integrally formed.

The distal anvil portion can include an anvil having a plurality ofpockets facing the cartridge supporting section. An elongated slot canbe formed in some embodiments in a surface opposite the anvil pocketsand extending longitudinally therealong wherein the anvil slot has afirst portion with a transverse dimension greater than a second portionand the second portion is closer to the cartridge supporting section.

BRIEF DESCRIPTION OF THE DRAWINGS

Various embodiments of the presently disclosed surgical fastenerapplying apparatus are described herein with reference to the drawingswherein:

FIG. 1 is a perspective view of the surgical fastener applying apparatusof the present disclosure shown in the clamped position with the firingknob in the pre-fired position;

FIG. 2 is an exploded view of the surgical fastener applying apparatusof FIG. 1;

FIG. 3 is a longitudinal cross-sectional view of the surgical fastenerapplying apparatus taken through line 3-3 of FIG. 1;

FIG. 4 is a perspective view similar to FIG. 1 showing the firing knobin the advanced position to fire the fasteners;

FIG. 5 is a transverse cross-sectional view of the surgical fastenerapplying apparatus taken along line 5-5 of FIG. 2;

FIG. 5A is a transverse cross-sectional view of the surgical fastenerapplying apparatus taken along line 5A-5A of FIG. 2;

FIG. 6 is a view similar to FIG. 3 showing the firing knob retracted andthe anvil supporting section unclamped from the cartridge supportingsection;

FIG. 7 is a perspective view showing the individual components separatedfor respective disposal and cleaning.

DETAILED DESCRIPTION

Embodiments of the presently disclosed surgical fastener applyingapparatus in accordance with the present disclosure will now bedescribed in detail with reference to FIGS. 1-7, wherein like referencenumerals identify similar or identical structural elements. As usedherein, as is traditional, the term “proximal” refers to the end of theapparatus which is closer to the user and the term distal refers to theend of the apparatus which is further away from the user.

Turning to FIGS. 1-3, one embodiment of the presently disclosed surgicalfastener applying apparatus is shown generally identified as surgicalstapler 10. Surgical stapler 10 includes an anvil supporting orhalf-section 100 and a cartridge supporting or cartridge receivinghalf-section 200. The anvil supporting section includes a clamping lever300. That is, as described in more detail below, the anvil supportingsection 100 and clamping lever 300 are integral so as to form a singleunit. This minimizes the components of the surgical instrument. Adisposable assembly includes a single use loading unit 400 (hereinafter“SULU”) and a firing unit 500. Each of these components or assemblieswill be described in greater detail below.

Anvil half-section 100 and cartridge receiving half-section 200 may beconfigured as reusable components and, as such, are constructed frombiocompatible materials suitable for sterilization and repeated use,e.g., stainless steel. SULU 400 and firing unit 500, on the other hand,are disposable. The SULU 400 and firing unit 500 are separatecomponents. Separation of the anvil half section 100 and cartridge halfsection 200 of stapler 10 is illustrated in FIG. 7.

SULU 400 and firing unit 500, may be constructed from any suitablebiocompatible materials, e.g., plastics, metals, or combinationsthereof. Further, surgical stapler 10 may be configured to receive oraccommodate disposable assemblies of various different configurations,e.g., disposable assemblies including SULU's and firing assemblies forfiring staples of different staple line lengths (e.g., 60 mm, 80 mm and100 mm).

As will be described in greater detail below, anvil half-section 100 andcartridge-receiving half-section 200 are releasably pivotably engagablewith one another in a plier like manner. More specifically, anvil halfsection 100 includes a distal anvil (fastener receiving) region orportion 102, a proximal clamping region or portion 104 which also formsa handle region, and an intermediate region or portion 106 extendingbetween (joining) the anvil region 102 and the clamping region 104. Theanvil half section 100 is pivotably coupled to cartridge-receivinghalf-section 100 about the intermediate region 106. Clamping region 104is pivotable relative to cartridge-receiving half-section 200 between aspaced-apart position (FIG. 6) and an approximated position (FIGS. 1 and3) for moving cartridge-receiving half-section 200 and anvilhalf-section 100 relative to one another between an open, or un-clampedposition and a closed, or clamped position (FIGS. 1 and 3) for clampingtissue therebetween. With surgical stapler 10 in the clamped position,firing unit 500 may be operated to sequentially fire and form aplurality of surgical staples 402 (FIG. 2) about tissue clamped betweenanvil half-section 100 and cartridge-receiving half-section 200 and foradvancing a knife 440 to divide tissue between the stapled portionsthereof.

Due to the pliers type arrangement, when the clamping lever 300 ofclamping region 104 is moved in a first direction toward the cartridgereceiving half section 200 (upwardly in the orientation of FIG. 1), thedistal anvil region 102 is moved toward the cartridge receiving section200 in a second opposite direction (downwardly in the orientation ofFIG. 1). This is described in more detail below.

Continuing with reference to FIGS. 1-3, distal anvil region 102terminates in nose portion 107. Proximal clamping region 104 has anupper surface 103 and an opposing lower surface 105, as viewed in theorientation of FIGS. 1 and 3. Anvil region 102 includes staple deformingportion 108 which includes a plurality of staple deforming recesses 111defined therein. These recesses 111 are formed on the lower surface,facing toward the tissue clamped between the anvil and cartridge halfsections 100, 200. Staple deforming portion 108 is disposed in opposingrelation relative to SULU 400 when the SULU 400 is engaged withinchannel member 206 of cartridge-receiving half-section 200. Further,staple deforming portion 108 includes a central longitudinal slot 130(FIG. 5) for receiving knife 440 of SULU 400 as the knife 440 isadvanced through SULU 400 to divide the stapled tissue. Staple deformingportion 108 can be formed integrally with anvil half-section 100 or,alternatively, may be secured to anvil half-section 100 by any suitablefastening process, e.g., welding.

Staple deforming portion 108 is positioned on the side of anvilhalf-section 100 facing toward the cartridge receiving half-section 200(and SULU 400). Knife slot 130, as shown in FIG. 5, extends toward theopposing side of anvil half-section 100. As shown, knife slot 130 has anarrowed region 132 to accommodate sliding movement of the knife 440.Knife slot 130 further progressively increases in width (transversedimension) away from the cartridge receiving half-section 200 (towardthe opposing side of anvil half-section 110) to form a widened slotregion 134 to facilitate cleaning of the anvil. Thus, a through slotalong the length of the distal anvil region 102 is provided, taperinginwardly to reduce entry of unwanted debris during the procedure, whileproviding a progressively increased width to facilitate access forcleaning.

A pair of fingers can be disposed adjacent intermediate portion 106 ofanvil half-section 100 provide a tissue stop.

Anvil half-section 100 can further include a pair of transversely-spacedextensions which extend towards cartridge receiving section 200. Theextensions are configured to contact a surface of a guide block (notshown) as surgical stapler 10 is moved towards the clamped position,such that the guide block is pivoted from a first, locked position to asecond, unlocked position. This guide block and its function andstructure are described in detail in commonly assigned U.S. Pat. No.7,055,730 and application Ser. Nos. 61/494,985, filed Jun. 9, 2011 and61/521,070, filed Aug. 8, 2011, the entire contents of which areincorporated herein by reference.

A central portion of cartridge half-section 200 includes a lateralsupport member 212, preferably substantially conical in configuration.As shown, the support member 212 with enlarged head 212 a extendslaterally from a proximal region of the channel member 206. Duringassembly of anvil half-section 100 and cartridge-receiving half-section200, lateral support member 212 is supported in notch 114 defined in aintermediate region 106 of anvil-receiving half-section 100 (FIG. 2).Lateral support member 212 provides for pivotal engagement of cartridgereceiving half section 200 and anvil receiving section 100 for clampingmovement in a plier type manner. The engagement of support member 212and notch 114 limits lateral movement of the half sections 100, 200.Proximal handle portion 102 of anvil half-section 100 is ergonomicallyformed and includes a thumb-engaging abutment 117. Cartridge receivingsection 200 also has an ergonomically formed thumb engagement member217.

A proximal end of handle portion 104 includes a locking projection 119.Locking projection 119 extends proximally from the proximal end ofclamping portion 300 and is designed to interact with the proximallypositioned locking member 216 of cartridge-receiving half section 200discussed below.

Cartridge-receiving half-section 200 includes an elongated channelmember 206 at a distal region (section) having a substantially U-shapedchannel 208 defined therein that is configured to releasably receiveSULU 400. On the opposing side, at a proximal region (section), aproximal channel is provided to receive the firing unit 500.Consequently, as viewed in the orientation of FIG. 2, the SULU 400 istop loaded into the channel 208 and the firing unit 500 is bottom loadedinto the proximal channel.

It is also contemplated, that due to the configuration of thecomponents, the firing unit 500 could alternately be top loaded into achannel formed in the proximal region 104 of the anvil receiving section102. In this case, the firing knob would be mounted to the anvil section100 and the cam bars of SULU 400 would extend into the cartridge halfsection 100 for alignment with the fasteners.

The proximal end of cartridge-receiving half-section 200 includes alocking member 216. Locking member 216 includes shelf 218 configured toengage projection 119 when the anvil half-section 100 is clamped to thecartridge-receiving half-section 200 to provide a ratchet type lockingmechanism.

When clamping lever 300 is pivoted from an open position to a clampedposition (FIG. 3) projection 119 is forced past locking hook or shelf218, biasing lock 218 proximally as it passes along the angled wall andpast shelf 218. That is, when the stapler 10 is clamped, projection 119is forced past, then engages (rests atop as viewed in the orientation ofFIG. 3) transverse shelf 218 to hold the clamping lever 300 in thelocked (clamped) position as the latching of the locking member 216 andprojection 119 prevent separation of clamping lever 300 and anvilhalf-section 100.

To disengage the locking mechanism, the locking member 216 can bepivoted manually by the user away from the projection 119, therebyallowing release of the anvil half section 100.

Referring to FIGS. 2 and 3, firing unit (assembly) 500 includes a knifeactuating bar 544, a pair of cam bars 546, and a firing knob 509.

The cam bars 546 extend through slots 408 in SULU 400 to fire fasteners402 housed in SULU 400. That is, as cam bars 546 are moved distallythrough SULU 400, they contact pushers 406 contained in SULU 400 tosequentially fire the fasteners 402 through the rows of fastener slots407 in SULU 400.

A guide block such as guide block 48 of patent application Ser. No.61/494,985 and guide block 548 of application Ser. No. 61/521,070 can beprovided having three longitudinal slots; a slot to receive each of thecam bars 546 and another slot to receive the knife actuating bar 544.The guide block, if provided, can be axially fixed within the distal endof cartridge half section 200 and pivotal from the first position inlocking engagement with knife actuating bar 544 to the second positiondisengaged from knife actuating bar 544 in response to movement ofstapler 10 to the clamped position. As anvil supporting 100 isapproximated relative to cartridge-receiving half-section 200 to achievethe clamped position, extensions on anvil supporting 100 urge the guideblock to pivot from the first engaged position to the second disengagedposition to disengage the lockout mechanism to enable firing of thefasteners.

Firing knob 509 includes an aperture 511 to receive post 513. Firingknob 509 is pivotal about post 513 so that the stapler can be fired,i.e. the cam bars 546 advanced distally, from either side of thestapler. That is, finger engagement member 512 a or 512 b can beselectively engaged by the user to move the firing unit 500 through afiring stroke, depending on the position of firing knob 509. As usedherein, a firing stroke is defined as movement of firing knob 552 from aretracted position of FIG. 3 to a fully advanced position of FIG. 4.

Knife actuating bar 544 includes an upturned hook portion and upper andlower notches. A finger projects upwardly from the knife actuating bar544. When the firing knob 509 is advanced distally, it moves to advancethe cam bars 546, and further distal movement effects distal movement ofknife actuating bar 544. This arrangement allows for staples to beejected from SULU 400 prior to cutting of tissue. Details of the knifeactuating bar are disclosed in application Ser. No. 61/494,985previously incorporated herein by reference in its entirety.

Referring to FIG. 2, each cam bar 546 includes a distal portion 547 anda proximal portion supported within housing 507. The proximal end ofeach cam bar is fixedly attached to slide block 515 from which post 513extends. Alternately, slide block 515 may be molded about the proximalend of cam bars 546. In one embodiment, the slide block 515 has a pairof slots to receive the cams bars 546. Due to this attachment, whenfiring knob 509 is advanced distally, it moves cam bars 546 distallythrough the slots 408 in the SULU 400 so that angled caroming surfaces548 at the distal portion 547 of cam bars 544 contact pushers 406 tofire the fasteners 402 in a direction substantially perpendicular to thelongitudinal axis of the cam bars 546 (substantially perpendicular tothe direction of movement of the cam bars 546).

Cartridge-receiving further includes lockout pins 541 formed in housing507. A slot in the outer surface of each cam bar 546 is engagable with arespective lockout pin 541 to prevent inadvertent advancement of the cambars 546.

Channel 208 engages and retains SULU 400 therein as wall 206 engagesSULU 400 to enclose the underside of cartridge body 420 of SULU 400.Thus, SULU 400 is fixedly secured within channel 206 via a snap-fitengagement. Other securement methods are also contemplated.

SULU 400 includes cartridge body 420, a plurality of staple pushers 406,a knife 440 having an angled sharpened leading edge or blade 441, and aplurality of staples 402. A pivotally mounted safety lockout could alsobe provided as in safety lockout 128 of the 61/494,985 application andsafety lockout 428 of application Ser. No. 61/521,070 (incorporated intheir entirety by reference above). Body 420 has a plurality of rows ofstaple retaining slots 430, e.g., four, six, etc. and a linear slottedknife track 452 centrally disposed therein. Knife 440 includes adownturned hook portion which is positioned to engage upturned hookportion of knife actuating bar 544 of firing unit 500. In theillustrated embodiment, body 420 includes two staggered rows of slots430 formed on either side of linear slotted knife track 452. Thestaggered rows of slots 430 extend beyond the distal end of knife track452 to facilitate staple formation beyond the distal end of the strokeof the knife blade 440 a, although other configurations arecontemplated.

Staple pushers 406 may be configured to extend into one or more slots430. In one embodiment, a single pusher is associated with each slot430. Alternatively, each pusher 406 can be configured to extend into twoadjacent slots 430 and is positioned beneath respective staples 402which are retained in slots 430. Further, each pusher 406 includes alower cam surface which is positioned for engagement by one of camsurfaces 548 on the distal portion 547 of cam bar 546 such that movementof cam bar 546 through SULU 400 sequentially lifts each respectivepusher 406 within its respective slot or slots 430 to eject staples fromslots 430.

A proximal end of SULU 400 can include opposed, outwardly extendingserrated surfaces to facilitate gripping of the proximal end of SULU 400to facilitate for removal and/or replacement of SULU 400 (or disposableassembly 600) from channel member 206 of cartridge-receivinghalf-section 200. The housing 507 of firing unit 500 can also includeopposed outwardly extending serrated surfaces to facilitate gripping offiring unit 500 for removal and/or loading into the proximal channel ofcartridge receiving half section 200.

A safety lockout 428 of the type described in patent application Ser.Nos. 61/521,070 and in 61/494,985 (lockout 128) can be provided. Whenthe knife 440 is moved towards the advanced position during a firingstroke, the safety lockout can pivot towards the unlocked position. Thesafety lockout is prevented from pivoting to the unlocked position whenthe anvil half-section 100 and cartridge-receiving half-section 200 arein the clamped position because the top surface of the safety lockoutengages an inner surface of anvil half-section 100 to prevent pivotingof the safety lockout.

The assembly and operation of surgical stapler 10 will now be described.Initially, disposable SULU 400 is engaged within cartridge-receivinghalf-section 200. In order to engage disposable SULU 400 withincartridge-receiving half-section 200, SULU 400 is generally alignedabove cartridge-receiving half-section 200 and is inserted into U-shapedchannel 208 of channel member 206. Installation may be facilitated, asdiscussed above, by grasping serrated surfaces of SULU 400. Firingassembly 500 is separately loaded into cartridge receiving half section200 by first aligning it below the proximal handle region and insertingit into the proximal channel. Serrated surfaces of housing 507, asdiscussed above, can facilitate loading. It should be appreciated thatreference to top loading and bottom loading are used for the orientationof cartridge receiving section shown in FIG. 2. Clearly, if theorientation changes, such loading references would also change, but theSULU 400 and firing unit 500 will still be loaded in opposing directionson opposite sides of the cartridge receiving section 200.

Once firing unit 500 and SULU 400 are loaded into cartridge half section200, anvil half-section 100 can be assembled to cartridge-receivinghalf-section 200. To attach anvil half-section 100 tocartridge-receiving half-section 200, transverse post or support member212 is positioned in notch 114 of anvil half-section 100. Thereafter,anvil half-section 100 is rotated towards cartridge-receivinghalf-section 200, thus moving distal anvil region 102 in a seconddirection toward SULU 400 as the clamping lever 300 is moved in a firstdirection toward the handle portion 210 of cartridge half section 200.Thus as can be appreciated, the anvil and cartridge half-sections 100,200 move in a pliers type manner into an approximated position to clamptissue between anvil region 102 and SULU 400. In this clamped position(e.g. FIG. 3), surgical stapler 10 is ready for use. Note in thisposition, the firing knob has been rotated to locate either fingerengagement member 512 a or finger engagement member 512 b in positionfor engagement by the user.

In other words, in use, with surgical stapler 10 in the open, orunclamped position (which corresponds to the position of FIG. 6,although FIG. 6 shows the stapler unclamped after firing), surgicalstapler 10 is manipulated into position such that tissue to be stapledand divided is disposed between anvil half-section 100 andcartridge-receiving half-section 200. Thereafter, surgical stapler 10may be moved to the clamped position to clamp tissue between SULU 400and staple deforming portion 108 of anvil half section 100. In order toposition surgical stapler 10 in the clamped position, clamping lever300, which is part of anvil half section 100, is rotated in acounter-clockwise direction to the position shown in FIG. 1. As clampinglever 300 is rotated, anvil half section 100 pivots about lateralsupport member 212. In this position, as shown in FIG. 1, stapledeforming portion 108 is positioned in close approximation with the topsurface of SULU 400.

As the clamping lever 300 is moved to the clamped position, projection119 of clamping lever 300 is forced past locking member 216 of cartridgehalf section 200, flexing the locking member 216 out of the way. Afterpassing by shelf 218, locking member 218 returns to its initial positionso that shelf 218 engages and blocks projection 119, thereby preventingseparation of the clamping lever 300 and cartridge half-section 200.Thus, in this clamped position, the engagement of shelf 218 andprojection 119 locks the clamping lever 300 in the clamped or lockedposition which locks the anvil half-section 100. This latch is releasedupon proximal movement of locking member 218 to disengage shelf 218 fromprojection 119.

If a guide block is provided as discussed above, as surgical stapler 10is moved to the clamped position, extensions of anvil half-section 100are approximated relative to cartridge half section 200 such that theextensions eventually contact the upper surface of guide block and urgethe guide block to pivot in a generally counter-clockwise direction soit moves from the locked position to the unlocked position, to unlockthe knife actuating bar 544. This prevents movement of the knifeactuating bar 544 in relation to the guide block prior to clamping, thusensuring that the knife actuating bar 544 and knife 440 remain properlypositioned for operational engagement prior to use.

When stapler 10 is in the clamped, unfired position, firing unit 500 isin the retracted position at the proximal end of the cartridgehalf-section 200. Firing knob assembly 509 is in a proximal position.Latch portion (hook) 218 of locking member 216 is engaged withprojecting surface 119 to retain clamping lever 300 in the clampedposition (FIG. 3).

When slide block 515 is in this retracted position, knife 440 and camsurfaces 548 of cam bars 546 are positioned in the proximal end of SULU400. If a safety lockout is provided, in this position, safety lockoutis retained in the locked orientation. In addition, the downturned hookportion of knife 440 is engaged with the upturned hook portion of knifeactuating bar 544 to connect firing unit 500 to knife 440 of SULU 400.

When the firing knob 509 is advanced distally to the position of FIG. 4to fire the fasteners as shown in FIG. 4, slide block 515 is moveddistally within a channel of handle portion 210 to move cam bars 546through slots 408 of SULU 400 and to move to knife actuating bar 544distally. As cam bars 546 are moved distally, cam surfaces 548sequentially engage pushers 406 to eject staples 402 from slots 407 ofbody 420. Concurrently, since the distal end of knife actuating bar 544is engaged with knife 440, knife 440, after the preset delay, isadvanced through SULU 400 to incise tissue between the staple lines.

After firing of the fasteners 402, firing knob 509 is returned to itsproximal position of FIG. 1 to retract cam bars 546 and knife 440 afterfiring. The locking member 216 can be manually released as describedabove, and the clamping lever 300 rotated counterclockwise away fromcartridge half section 200 to separate anvil half-section 100 fromcartridge-receiving half-section 200 as clamping lever 300 movesdownwardly away from cartridge receiving section 100 and distal anvilregion 102 moves upwardly away from SULU 400 as shown in FIG. 6. Theanvil half section 100 and cartridge half section 200 can then beseparated as shown in FIG. 7 by disengaging lateral member 212 fromnotch 114. Note in this open position, if the aforementioned safetylockout is provided, the safety lockout moves to its unlocked positionsuch that it projects upwardly from SULU 400 to prevent movement of thestapler 10 back to the clamped position. In order to reuse stapler 10,used SULU 400 must be replaced with a new SULU 400.

During a surgical procedure, SULU 400 and firing unit 500 can bereplaced multiple times to facilitate multiple uses of stapler 10 on asingle patient. Each disposable SULU 400 is provided with a fresh knife.Further, each fresh firing unit 500 is provided with fresh cam bars 546and firing knob 509, thus inhibiting fatigue or wear of any of thecomponents thereof and simplifying the number and form of componentsbeing resterilized. After the surgical procedure, the SULU 400 andfiring unit 500 can be removed from cartridge half section 200 anddisposed of in an appropriate manner.

The anvil half-section 100, with integral clamping lever 300, andcartridge receiving half-section 200 on the other hand, can besterilized, such as by autoclaving, and reused with a new disposableSULU 400 and firing unit 500 in the manner discussed above. Because thefiring unit 500 and SULU 400 are all disposable, fewer areas remain onthe reusable components for tissue and fluids to become trapped. Assuch, the reusable components of the apparatus can be more easilysterilized.

It will be understood that various modifications may be made to theembodiments of the surgical fastener applying apparatus disclosedherein. Therefore, the above description should not be construed aslimiting, but merely as exemplifications of embodiments. Those skilledin the art will envision other modifications within the scope and spiritof the present disclosure.

What is claimed is:
 1. A method of assembling and firing a surgicalfastener applying apparatus, the method comprising: inserting a loadingunit having an upper surface defining a plane and a plurality offasteners into a channel defined by a distal cartridge portion of acartridge receiving half-section from a first side of the cartridgereceiving half-section; loading a firing assembly into a proximal handleportion of the cartridge receiving half-section from a second side ofthe cartridge receiving half-section opposite the first side of thecartridge receiving half-section; and assembling the cartridge receivinghalf-section with an anvil half-section such that a distal anvil regionof the anvil half-section is positioned on the first side of thecartridge receiving half-section and a proximal handle region of theanvil half-section is positioned on the second side of the cartridgereceiving half-section, wherein the distal anvil region of the anvilhalf-section is positioned on one side of the plane and the proximalhandle region of the anvil half-section is positioned on an oppositeside of the plane.
 2. The method according to claim 1, wherein insertingthe loading unit includes grasping serrated surfaces of the loadingunit.
 3. The method according to claim 1, further comprising pivotingthe distal anvil region of the anvil half-section towards the distalcartridge portion of the cartridge receiving half-section by moving theproximal handle region of the anvil half-section towards the proximalhandle portion of the cartridge receiving half-section.
 4. The methodaccording to claim 1, wherein assembling the cartridge receivinghalf-section with the anvil half-section includes engaging anintermediate region of the anvil half-section that is disposed betweenthe distal anvil region and the proximal handle region with a supportmember of the cartridge receiving half-section.
 5. The method accordingto claim 4, wherein engaging the intermediate region with the supportmember includes receiving the support member within a notch defined bythe intermediate region.
 6. The method according to claim 1, furthercomprising firing the surgical fastener applying apparatus bytranslating a cam bar of the firing assembly distally to engage theplurality of fasteners.
 7. The method according to claim 1, furthercomprising locking the anvil half-section and the cartridge receivinghalf-section relative to one another with a locking mechanism positionedon the proximal handle portion of the cartridge receiving half-sectionand the proximal handle region of the anvil half-section.
 8. A method ofassembling and firing a surgical fastener applying apparatus, the methodcomprising: loading a firing assembly into an elongated channel of aproximal handle portion of a cartridge section of the surgical fastenerapplying apparatus; moving a proximal handle region of an anvil sectionof the surgical fastener applying apparatus in a first direction towardsthe proximal handle region of the cartridge section to move a distalanvil region of the anvil section in a second direction opposite thefirst direction towards a distal cartridge portion of the cartridgesection to clamp tissue between the distal anvil region and the distalcartridge portion; and firing the surgical fastener applying apparatusby distally translating a cam bar of the firing assembly through theelongated channel to engage a plurality of fasteners in the distalcartridge portion of the cartridge section.
 9. The method according toclaim 8, further comprising inserting a loading unit having a pluralityof fasteners into a channel defined by a distal portion of the cartridgesection from a first side of the cartridge section.
 10. The methodaccording to claim 8, wherein firing the surgical fastener applyingapparatus includes moving a firing knob of the firing assembly from aproximal position to a distal position to distally translate the cambar.
 11. The method according to claim 8, further comprising disposingof the firing assembly after firing the surgical fastener applyingapparatus.
 12. The method according to claim 8, further comprisinglocking the anvil section and the cartridge section relative to oneanother with a locking mechanism positioned on the proximal handleportion of the cartridge section and the proximal handle region of theanvil section before firing the surgical fastener applying apparatus.13. A method of assembling and firing a surgical fastener applyingapparatus, the method comprising: top loading a cartridge having aplurality of fasteners into a channel defined by a distal cartridgeportion of a cartridge section of the surgical fastener applyingapparatus from a top side of the cartridge section; bottom loading afiring assembly into the cartridge section from a bottom side of thecartridge section; moving a proximal handle region of an anvil sectionof the surgical fastener applying apparatus from an unclamped positionto a clamped position relative to a proximal handle portion of thecartridge section to approximate a distal anvil region of the anvilsection with the cartridge section; engaging the cartridge section witha locking member of the proximal handle region of the anvil section; andmoving a firing knob of the firing assembly from a proximal position toa distal position to fire the plurality of fasteners from the cartridge.14. The method according to claim 13, wherein bottom loading the firingassembly includes bottom loading the firing assembly into the proximalhandle portion of the cartridge section.
 15. The method according toclaim 13, further comprising assembling the cartridge section with theanvil section by engaging an intermediate region of the anvil sectionthat is disposed between the distal anvil region and the proximal handleregion with a support member of the cartridge section.
 16. The methodaccording to claim 15, wherein engaging the intermediate region with thesupport member includes receiving the support member within a notchdefined by the intermediate region.
 17. The method according to claim13, further comprising removing the firing assembly after firing thesurgical fastener applying apparatus.
 18. The method according to claim13, further comprising sterilizing and reusing the cartridge section andthe anvil section after moving the firing knob from the proximalposition to the distal position.